cheekyoudaoicibaDictYouDict[cheek 词源字典]
cheek: [OE] Old English cēace and cēoce go back respectively to prehistoric West Germanic *kǣkōn and *keukōn, but beyond that the word has no known relatives in other Indo-European languages. It has, however, produced one or two interesting offshoots. It forms the basis of the verb choke, and may be the source of chock-full (literally, ‘full up to the cheeks’); and Middle Dutch kākelen, source of English cackle [13], may be partly based on the related Middle Dutch kāke ‘jaw’. The metaphorical sense ‘impudence’ (whence cheeky) arose in the 19th century, originally as ‘insolent talk’.
=> cackle, chock-full, choke[cheek etymology, cheek origin, 英语词源]
cheek (n.)youdaoicibaDictYouDict
Old English ceace, cece "jaw, jawbone," in late Old English also "the fleshy wall of the mouth." Perhaps from the root of Old English ceowan "chew" (see chew (v.)), or from Proto-Germanic *kaukon (cognates: Middle Low German kake "jaw, jawbone," Middle Dutch kake "jaw," Dutch kaak), not found outside West Germanic.

Words for "cheek," "jaw," and "chin" tend to run together in IE languages (compare PIE *genw-, source of Greek genus "jaw, cheek," geneion "chin," and English chin); Aristotle considered the chin as the front of the "jaws" and the cheeks as the back of them. The other Old English word for "cheek" was ceafl (see jowl).
A thousand men he [Samson] slow eek with his hond,
And had no wepen but an asses cheek.
[Chaucer, "Monk's Tale"]
In reference to the buttocks from c. 1600. Sense of "insolence" is from 1840, perhaps from a notion akin to that which led to jaw "insolent speech," mouth off, etc. To turn the other cheek is an allusion to Matt. v:39 and Luke vi:29.